利用 ggplot2 套件繪圖

郭耀仁

2017-12-02

ggplot2

載入 tidyverse 與 gapminder

library(tidyverse)
library(gapminder)

The best stats you’ve ever seen

https://youtu.be/jbkSRLYSojo

相關：數值 vs. 數值

ggplot() + geom_point() 繪製散佈圖

gapminder_2007 <- gapminder %>%
  filter(year == 2007)
ggplot(gapminder_2007, aes(x = gdpPercap, y = lifeExp)) +
  geom_point()

aes() 中加入 color =

ggplot(gapminder_2007, aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point()

log_scale

ggplot(gapminder_2007, aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  scale_x_log10()

線圖：時間 vs. 數值

ggplot() + geom_line() 繪製線圖

gapminder_tw <- gapminder %>%
  filter(country == "Taiwan")
ggplot(gapminder_tw, aes(x = year, y = lifeExp)) +
  geom_line()

多個線條

gapminder_na <- gapminder %>%
  filter(country %in% c("China", "Hong Kong, China", "Japan", "Korea, Rep.", "Taiwan"))
ggplot(gapminder_na, aes(x = year, y = lifeExp, color = country)) +
  geom_line()

散佈

ggplot() + geom_histogram() 繪製直方圖

ggplot(gapminder_2007, aes(x = lifeExp)) +
  geom_histogram(bins = 40)

ggplot() + geom_boxplot() 繪製盒鬚圖

ggplot(gapminder_2007, aes(x = continent, y = lifeExp)) +
  geom_boxplot()

直方圖加入 facet_wrap()

ggplot(gapminder_2007, aes(x = lifeExp, fill = continent)) +
  geom_histogram(bins = 20) +
  facet_wrap(~continent, nrow = 2)

排名（類別 vs. 數值）

垂直長條圖 ggplot() + geom_bar(stat = "identity")

gapminder_2007_na <- gapminder_2007 %>%
  filter(country %in% c("China", "Hong Kong, China", "Japan", "Korea, Rep.", "Taiwan"))
ggplot(gapminder_2007_na, aes(x = country, y = gdpPercap)) +
  geom_bar(stat = "identity")

水平長條圖 + coord_flip()

ggplot(gapminder_2007_na, aes(x = country, y = gdpPercap)) +
  geom_bar(stat = "identity")+ 
  coord_flip()

在一個畫布上畫多個圖形

  • 使用 gridExtra 套件來幫忙
  • grid.arrange() 函數
install.packages("gridExtra")
library(gridExtra)

gg1 <- ggplot(gapminder_2007_na, aes(x = country, y = gdpPercap)) +
  geom_bar(stat = "identity")
gg2 <- ggplot(gapminder_2007_na, aes(x = country, y = gdpPercap)) +
  geom_bar(stat = "identity")+ 
  coord_flip()
grid.arrange(gg1, gg2, nrow = 2)

ggplotly() 加入互動性

  • 使用 plotly 套件的 ggplotly() 函數
install.packages("plotly")
library(plotly)
static_gg <- ggplot(gapminder_2007, aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  scale_x_log10()
ggplotly(static_gg)

R 語言的互動性解法

文件